We found this circuit in a 1994 National Semiconductor technical documentation. The circuit can be adapted to operate with more modern equivalent operational amplifiers.
This circuit was found on an application note from Linear Technology of the 1990s. The source must...
Using only one integrated circuit this control was found in an 80's Electronic Engineering. The circuit...
The transistor in this circuit can be the BC558 and the capacitors must be ceramic. Crystals from...